Display sign



Nov. 5, 1935. B. TRESHANSKY ET AL 2,029,087

DISPLAY SIGN Filed July 14, 1952 5 m 4m e Patented Nov. 5, 1935 UNITED STATES PATENT OFFIQE DISPLAY SIGN Application July 14, 1932, Serial No. 622,382

12 Claims.

The present invention relates generally to display signs such as are used in store windows and like placesfor advertising purposes, and has particular reference to an improved display sign of 61 this type which operates on optical principles to secure an intermittent automatic change of the images presented for View. The sign is of translucent material and the optical change is effected by projecting light rays through the sign for pre- 10, senting one picture and then discontinuing the projection of the light rays through the sign for presenting another picture.

The primary object of the invention is to provide an improved display sign which iscapable of 16. presenting two totally distinct pictures or images in this manner. This involves completely obliterating one image or picture when the light rays are being projected through the sign, so that only the other image or picture appears. I-Ieretofore, the majority of these display signs have been limited to the use of the same image outline for both pictures, the permissible variation being merely the superposition on this image outline of additional features of detail, color, etc. In view of 25.1` the fact that the picture which is presented in our improved sign when no light rays are projected through the sign, is completely obliterated when the light rays are projected through the sign for displaying the second picture, we are enabled to present two totally distinct pictures, which might even bear no relation to each other whatever in either outline or composition, if such were desirable ior the particular advertising use. By way of example, our improved sign is capable 351'V of alternately presenting to View a vacant lot and then a bungalow; an old dilapidated house and then an apartment building; a horse and buggy and then anI automobile; an egg and then a chick, etc.

Another object of the invention is to provide an improved method of making a sign or composite picture having this characteristic. The general principle underlying such method is that when a photographic negative and a photographic positive of the same image are superpo'sed on each other in exact registry the shadows of, the one neutralize the high lights on the other, and vice versa, so that a uniform intensity of light will then be projected through the composite over 50i every unit of area with no denition of the original: image appearing. These light rays, projected through the second, totally distinct picture, take on none` of the denition of the rst image.`

Other objects and advantages of our invention 552 Willil appear.` from the following detail description method of alternately illuminating the sign. 10,

The other gures illustrate the method steps of producing the sign.

Figure 2 illustrates the original photographic negative of the image or picture which is to appear when no light rays are projected through l the sign;

Figure 3 illustrates a positive reproduction of the original negative of Figure 2, such positive reproduction being made on translucent print paper or other suitable base material; 20:.

Figure 4 is a positive reproduction of the original negative of Figure 2, made on film, photographic plate or the like;

Figure 5 illustrates the original photographic negative of the second image or picture which is 26 to appear when light rays are projected through the sign, and

Figure 6 is a composite reproduction of the positive of Figure 4 and the original negative oi Figure 5, such composite reproduction being pref- 30 erably Yon translucent print paper or other suitable base material.

Referring first to Figure 1, the translucent sign is generally indicated at Iii, comprising a front sheet II and a rear sheet I2, on which V the images or pictures are reproduced. To protect these sheets from moisture, atmospheric changes, the temperature of the light rays, etc.,

f the front and backv sides of the two sheets are covered by transparent panes of glass Ill and I5. This assembly of the sheets and glass panes is supported in a suitable frame structure I6, arranged in any desired manner for quickly and easily interchanging the sheets Il, I 2. Extending rearwardly from the frame I6 is any suitable 45 form of reflector I8 within which one or more lights i9 are mounted.

The sign operates entirely successfully when ordinary daylight, or any diminished value thereof available in a store window, is utilized to illuminate the front side of the sign for presenting one picture, and the light rays from one or more lights I 9 are projected through the sign for presenting the other picture. In such uses, it may be desirable to shroud. or hood the front of the sign by a hood 2| extending from the top and sides of the sign, so as to give greater contrast or preponderance to the light rays projected through the sign from the light I9. We also contemplate an embodiment wherein greater contrast or preponderance between the alternating light values can be obtained by placing a front light 24 in position to project its rays against the front of the sign, and by operating the lights I9 and 24 alternately. In such latter embodiment, the front light 24 may be supported in the hood 2|, with a suitable reector 25 so positioned as to project the majority of the light rays therefrom down upon the front side of the sign. The back and front lights I9 and 24 can be illuminated alternately by any desired flasher switch, motor driven switch or the like. In Figure l we have illustrated a thermally operated flasher switch 21 which may be employed for this purpose. The latter comprises a suitable thermostatic element, such as a bimetallic strip 28 over which is wound a heating coil 29. A movable switch element comprising two contacts 3| and 32 is -actuated by this thermostatic element. The two contacts 3| and 32 are mounted in insulated relation, as diagrammatically represented by the insulating blocks 33. The contact 3| is adapted to engage with a contact 34 connecting through wire 35 leading to the rear light I9, and the other movable contact 32 is adapted to engage with contact 36 connecting through wire 3'| leading to the front light 24. Any suitable snap actuating mechanism, such as is diagrammatically indicated at 38, may be employed for transmitting motion from the thermostatic strip 28 to the movable contact elements 3|, 32 for snapping the latter from one circuit closing position to the other. 'I'he supply circuit is indicated at 43, 44, the wire 43 being connected to one end of the heating coil 29, and the wire 44 being connected to the other terminals of both lights I9 and 24. The opposite end of the heating coil 29 is electrically connected with the movable switch contact 3|. A shunt 45 bridges the heating coil 29, extending from the wire 43 to the other movable switch contact 32. When the switch is in the position causing contacts 3| and 34 to engage, the rear light I9 is illuminated and the current therefor is traversing the coil 29. When the thermostatic strip 28 reaches a suilicient temperature it fiexes in a direction to throw the switch to the opposite position, thereby separating the contacts 3| and 34 and engaging the contacts 32 and 36. This cuts 01T the rear light I9 and illuminates the front light 24, the current for the latter passing through the shunt 45. When the thermostatic strip 28 has cooled to a suiiicient degree it flexes in the opposite direction and thereby throws the movable switch contacts back to their preceding positions.

Referring now to the preferred method of producing our changeable sign II, I2, we shall assume that the picture to be displayed by exterior light or by the rays from the front light 24 is that of an old, dilapidated house and that the picture to be presented by the rays projected through the sign from the rear light I9 is that of a modern, attractive apartment building, which type of sign might conceivably be used for advertising purposes in a real estate ofce and which, for the purposes of the present disclosure, illustrates two widely contrasting images having no lines of deiinition in common.

The rst step is illustrated in Figure 2, consisting in the making 0f a photographic repro-I duction of the house. The photograph may be taken of an actual house, or it may be taken of a drawing, painting or other pictorial representation of a house. The result is an original negative 5I, preferably iilm, in which the high light 5 Y two positives are now made of this negative 5|;

one a positive reproduction on translucent print paper, designated II in Figure 3, and the other a positive reproduction on film, designated 52 in 15 Figure 4. In each of these the image A will appear in its natural light values, the high lights of the actual image appearing as high lights in both of these positive reproductions and the shadows appearing as shadows. The sheet II 20 of Figure 3 is the front sheet I| of the composite sign referred to in connection with Figure 1.

A photographic reproduction is now made of the second image which is to be presented when light rays are projected through the sign. This 25 photographic 'reproduction is represented by an original negative designated 53 in Figure 5. As previously remarked, this second image is that of an apartment building, and this image we shall refer to as image B. Here again, this photo- 30 graphic reproduction may be made from an actual building, or from a drawing, painting or other artistic representation of such building. Of

course, the high lights of the original image also appear dark in such negative and the shad- 35 ows light.

Figure 6 illustrates the next step-that of making a composite print prepared from the two lms 52 and 53. This print, which is the sheet I2 of Figure l, is preferably on translucent print o paper, and is preferably a contact print, made with the two lms 52 and 53 one on top of the other in contact and held against the print paper. The reproduction on the paper I2 is a composition of images A and B. On this 45 sheet I2 the light values of image A" are reversed from the waytheyappearonsheet II, i. e., the high light areas on sheet II appear as low light areas on sheet I2 and the low light areas of sheet II appear as high light areas on sheet 60 I2. Referring now to image B, as also repro'- duced in this composite print I2, this image B has its true light values since it is a positive of negative 53, i. e., the high light areas of the building and other portions of image B appear 55 as corresponding high light areas in the composite print I2, and the same is true of the low light areas. The sheet I2 is thus a composite reproduction showing image A in its negative light values and showing image B in its posl- 60 tive light values.

The sheets I I and I2 are now brought into registry. 'I'his registry is obtained when the positive reproduction of image A appearing on sheet II is in register with the negative reproduction of image A appearing on sheet I2. Such registration might be effected mechanically by properly sized or perforated sheets, but a very simple and effective practice is to project light through the two sheets and move one 70 relatively to the other until image A completely disappears, whereupon registry between the positive counterpart of the image with the negative Ycounterpart is assured. The registered relation between the two sheets I I and I2 is then 75 sented. in this positive print; light ISisilluminated, or therearfsource of. light 2",02"008"7 `Isuermanently 1ixed, preferably lb'y .fiadhesively uniting the two sheets with a transparentadfhesiveapplied over their entire contacting areas;

.although thesheetsfm'ay only'be cemented-together at their edges or Ymight be mechanically clamped together.

In* displaying the sign as' describedabove'` in connection with Figure .1, image A-the house-will stand out as a prominent clear-cut picture as long as..theexternal light'y rays, either Sdaylightaorfrom' the -front light 24, predominate.

lAt .this time the-:light'rays'depicting the image orpicture'are solely raysre'ectedfrom the outer' surface v'of .the positive print'- I'I ,fand `a'llldetails of. the .image in their true `light values are" repre- When the rear preponderates over the frontisourcethe negativ'e *reproduction of image ".fA appearing on sheetll. becomes the optical or reverse counterpart of lthe positivereproducti'on `of image A appearing on sheet Il and hence'these negative and positive counterparts completelyflneutralize each other in so far'as givingdeiinition and graduated light 'values is concerned. Therefore,

`upon the illumination of vtherear Ylight I9, the

image Ais completely obliterated. These'same light-rays, however, Ain passingthrough'the rear sheet`I2, take onthe definition andgraduated light `values of Aimage B" which are reproduced in 'thisfrear sheet. Since the reproduction oi image B is positive-in composite' print I2, Vthe resultingpresentation of image B is in its true relation of light and dark areas.

The sheets II and I2are preferably highly translucent for transmitting fairly high light intensity, and the negative and positivecounterparts of image A appearing on sheets I2 and I I, respectively, are such thatthere are-no'totally opaque areas, at least over that part "of the VVframed areathrough whichit is desired to project a denedfportion'of image B. Neither of these considerations'imposesany Iobjectionable limitations 'again'st obtaining a clear-cut, well dened reproduction of image"A on sheet II for presentation Iwhen the rays `from -rear 'light I9 Yare interrupted. Therefore, by securing sufficient intensity of illumination from such rear light or Ylights I9, an adequate intensity o-f light can be projected through both sheets for "such is easily accomplished by appropriately tinting sheet I2. lThis is preferablyfdone-on the back side of sheet I2, although it might be done on the front side thereof before the two sheets arejoined together, and merely consists in appropriately coloring the areas of sheet I2 corresponding to the building, trees, shrubbery, etc. When image A is presented from light rays reflected from the surface of sheet II none of these colors will appear, but when light rays are projected through the sign these colors will clearly appear on image B, thereby heightening the contrast of before and after, where such is desirable.

It Vwill of course be understood that numerous modifications and rearrangements may be adopted without departing from the essence of the invention. For example, whilevwe have described the two original negatives 5I'andt531as -being'made-ion iilm, itv will of course beunderlstood that these original negatives-might be made on -pliotographically sensitized glass plates fsuchv as are extensively usedin commercial work. 5

Thesame is alsov true of the'lpositivereproduc- 'tion-'152 of Figure 4, which mightalso be madefon -a .glassv plate. l'claimswherever general reference is made to `one of ithese elements 5I, 52 or 53` as a sheet 10 Therefore, in the accompanying ora photographic sheet it will be understood that such contemplatesy either lilm or glass plate.

V-Inn'iakingthe composite print I2 it is-preferable gtousel two 'sheets of film,A bearing l`images"-A and B, 'inpreference to glass plates, in order 1.5 to'avoid'the possibleparallax of light rays-passing "through the greater thickness of the two glassy plates, but of course Vthese films vmightfbe reproduced from original Vglass platenegatives. Also, in lieuof print paper as the base'medium for the-translucent sheets I I and I2, any other appropriate basemedium might be used. vvl'or example, a material 'such as cellophane or like substance Inight be used as'V the base material for the sheets Il and I2, with the surface coated 25 with alight sensitive material. As an alternative, 'though'less desirable` method, the composite reproduction represented by the one'sheet I2 might in fact consist of two separate sheets,-

one a reproduction made from sheet 52 `andthe 30 other 'a reproduction made `from sheet 53. In this instance, however, the light rays would have vto pass through three translucent sheets instead of two. In any such three sheet method greater tran'slucency might be obtained by making -the 35 print 'of sheet 52' (in which print'image lA will be in negative) and making the print of sheet 53 (in which print image B will be fin positive)r ontwo separate sheets of celluloid lm -or like material and using these two sheets of film 'in 40 lieu of the composite print paper'sheet I2.

Having thus described our invention, whatwe claim as new and desire to secure by Letters Pat- 'ent 4of theUnited States is:

' 1. In'a vdisplay sign, the combination of `a'trans- 45 lucent front sheet having image A reproduced thereon in positive, a translucent rear sheet' having-1a composite reproduction thereon comprising image A in negative and'irnage B in positive, and means for projecting lightl rays through 50 said two sheets, said sheets being arranged whereby the projection of light rays therethrough causes the positive and negative reproductions of image A to form counterparts of reversed light transmitting value substantially to obliterate 55.

image A and to present B to view, and whereby the preponderating reflection of light rays from said front sheet presents image A to view.

2. In a' display sign, the combination of a transflucent front sheet having image A reproduced 50 fthereon in positive, translucent means disposed 'b'ehindsaid" front sheet having image A reproduced thereon in negative and image B in positive, and means for projecting light rays through said latter means and through said front sheet 55 whereby during the projection of said light rays the positive and negative counterparts of image A substantially obliterate said image and present image B to View.

3. In a display sign, a combination of a trans- 70 lucent front sheet having image A reproduced thereon in positive, a translucent rear sheet having a composite reproduction thereon comprising image A in negative and image B in positive, said sheets being arranged with the positive and negative counterparts of image A in registry, light projecting means disposed behind both sheets for projecting light rays therethrough, and means for causing intermittent projection of such light rays through said sheets, whereby when said rear light rays are interrupted front light rays reflected from said front sheet present image A to view and when said rear light rays are projected through said two sheets the positive and negative counterparts of image A substantially obliterate said image and present image B to view.

4. In a display sign, the combination of a translucent front sheet having image A reproduced thereon in positive, rear picture means of translucent material comprising image A in negative and image B in positive, the negative reproduction of image A on said rear picture means being in registry with the positive reproduction of image A on said front sheet, means for projecting rear light rays through said rear picture means and said front sheet, and means for causing the intermittent projection of such rays, whereby when said rear rays are interrupted the reflection of front light rays from said front sheet will present image A to View and whereby the projection of said rear light rays will substantially obliterate image A and present image B to View.

5. In a display sign, the combination of a source of light, a translucent sign disposed in front of said source of light, and means for intermittently interrupting the projection of light rays through said translucent sign, said sign comprising positive and negative reproductions of one image arranged in registry and a positive reproduction of a second image.

6. In a display sign, the combination of a translucent sign, a front source of light for projecting light rays adapted to be reilected from the front of said sign, a rear source of light for projecting light rays through said translucent sign, and means for causing the projection of light rays from said two sources to occur alternately, said translucent sign comprising positive and negative counterparts of one image arranged whereby said positive counterpart is brought to view by said front rays of light and the image is substantially eifaced by said rear rays of light, and comprising a positive reproduction of a second image which is brought to view by said rear rays of light.

7. The method of making a display sign of the class described, which comprises producing a photographic negative of image A, making two positive reproductions of said negative, one of a translucent sheet and the other on a photographic sheet, producing a photographic negative of image B, printing on a second translucent sheet a composite reproduction of said photographic sheet and said latter negative, and superposing one of said translucent sheets upon the other and negative counterparts of one picture, photo- 5 graphically producing a second picture, and bringing said reproductions together with the positive and negative counterparts of said first picture in registry.

9. In a display sign, the combination of a trans- 10 lucent sign reflecting front light rays striking the iront of said sign, a rear source of light for projecting rear light rays through said translucent sign, and means for causing the projection of said rear light rays through said sign to oc- 15 cur intermittently, said translucent sign comprising photographic positive and negative counterparts of oneI image arranged whereby said positive counterpart is brought to View by said front light rays reflected from said sign and the image is substantially eifaced by said rear light rays, and comprising a photographic positive reproduction of a second image which is brought to view by said rear light rays.

10. In a display device, the combination of a source of light, a translucent sign disposed in front of said source of light, and means for intermittently interrupting the projection of light rays through said translucent sign, said sign comprising front and back translucent sheets, a positive reproduction of image A on said front sheet,

a positive reproduction of image B on said rear sheet, and a negative reproduction of image A on one of said sheets in registry with said positive reproduction of image A,

11. In a display device, the combination of a source of light, a translucent sign disposed in front of said source of light, means for intermittently interrupting the projection of light rays through said translucent sign, said sign comprising front 4,0 and back translucent sheets, said sheets having photographically reproduced thereon the positive and negative counterparts of image A and the positive reproduction of image B arranged whereby when no light is projected through said sign from said source of light image A is brought to view, and when light is projected through said sign from said source of light the positive and negative counterparts of image A cooperate substantially to efface said image, and image B is brought to View.

12. The method of making a display sign, which comprises photographically producing a positive of image A on one sheet, photographically producing a positive of image B on another sheet, photographically producing a negative of image A on one of said sheets, and superposing one of said sheets upon the other with the photographic counterparts of image A in registry.

BERL TRESHANSKY. MEYER TRESHANSKY. 

